Danhua Zhao

A Yb³⁺-doped BiOI 3D nanosheet array composite was successfully fabricated through a solvothermal deposition strategy on flexible carbon cloth (CC). This composite was subsequently integrated with high-chlorine fly ash (FA) blocks to form the Yb-BiOI/CC/FA hybrid material. Comprehensive characterization was performed using multiple analytical techniques for crystalline phase identification, morphological analysis, valence state, band structure evaluation, and charge carrier separation assessment. Electrochemical measurements were conducted to evaluate the material’s electronic properties. Experimental results demonstrated superior photocatalytic performance under visible light irradiation, with the Yb-BiOI/CC/FA composite achieving 52.87% methylene blue degradation efficiency. The reaction rate constant of this modified nanomaterial was approximately 2.1 times higher than that of pristine BiOI/CC/FA. Radical trapping experiments revealed that superoxide radicals (·O₂⁻) served as the predominant oxidative species. This study presents a dual-benefit strategy for environmental remediation by simultaneously achieving sustainable waste valorization of industrial byproducts (FA) and developing high-efficiency photocatalytic materials. The successful integration of rare-earth metal modification with substrate engineering provides valuable insights for designing advanced photocatalytic systems for pollutant degradation.

Acid Red 138 (AR138) and Acid Green 27 (AG27) were efficiently removed from aqueous solutions via adsorption using modified blast-furnace slag (MBFS). The surface of MBFS was investigated using scanning electron microscopy and Brunauer–Emmett–Teller method. The effects of operating parameters such as adsorbent dosage, pH, and temperature on the dye removal were studied. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to describe the kinetics data. The equilibrium isotherms were analyzed using the Langmuir and Freundlich adsorption models. The experimental data fitted well to the pseudo-second-order kinetics model for AR138 and AG27. The Freundlich isotherm described the equilibrium data of acid dyes on MBFS better than the Langmuir isotherm. Furthermore, the thermodynamic parameters (ΔG₀ < 0, ΔH₀ < 0, and ΔS₀ < 0) showed that the adsorption reactions of AR138 and AG27 onto MBFS were feasible, spontaneous, and exothermic under the investigated conditions. Thus, MBFS is an effective biosorbent for the removal of acid dyes.

In this study, chemiluminescence (CL) behaviour of Luminol-H₂O₂ in the presence of the different concentrations of four surfactants, cetyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB), sodium dodecyl sulphate (SDS) and polyoxyethylene dodecyl ether (Brij-35), was investigated. A novel method for the direct determination of critical micelle concentration (CMC) of the surfactants using flow-injection CL is described. Under the optimum conditions, the luminescence intensity of the Luminol-H₂O₂ system increased gradually with increasing concentration of the surfactants before the CMC, but rapidly reached to the emission maximum at the CMC, followed by a decrease after the CMC. The concentrations of the surfactants corresponding to the luminescence maximum are in agreement with the literature CMC values. The main factors affecting the determination of CMC are discussed. The mechanistic studies show that the luminescence peaks observed in the experiment were mainly because of the protective effect of the micelle against the transition of the excited species and the retarding effect of the micelle structures on the CL reaction rate.

A new sorbent material, calcium fluoride-acid red 138 (AR138), was synthesized and characterized by various methods. The hybrid adsorbent for adsorption of PCBs corresponded to the octanol–water partition law, and their partition coefficients were calculated to be 5,836.8 mg kg⁻¹ for PCB029, 8,311.9 mg kg⁻¹ for PCB101, and 20,815 mg kg⁻¹ for PCB180, respectively. When the hybrid adsorbent was used in the treatment of a polluted ground water sample, the removal of PCB concentrations was satisfactory. All the reactants used in the synthesis of the adsorbent material are easily available and are harmless to the environment. Also, the AR138 reactant may reuse a concentrated AR138-producing wastewater instead. Therefore, this work has developed a simple, eco-friendly, and “waste treat waste” method for the large-scale production of a cost-effective sorbent.